I’m brainstorming some ideas for an electric bike in an ES forum, but my question is electrical…
If I have 2 separate vescs (w/ no canbus connection in-between) connected to the same battery, can I simultaneously drive/power 1 and use the other one for regen, say if I’m, cranking it with pedals? Would the battery reject this?
If I’m coasting I could let off the throttle but still crank… thereby putting juice back into the battery.
I’m about 50% sure the extra power coming out of the regen vesc will simply raise the voltage and the drive vesc will just pull from this somewhat… I think?
I can’t think of a reason why this wouldn’t work. Your motor outputting power would be using the same energy being generated and the battery would just supply the rest. Almost like a series electric drive, one motor generating power, charging the battery and then one motor for the drive wheel. Kind of like a series hybrid configuration in cars (Chevy volt) or other machines (D7E dozer). But instead of an engine charging the battery it would be your pedaling.
After reading about this topic, I do not recommend cranking as a regenerate due to a certain resistance regen braking would have on the petals (as they say). That and it’s very dangerous and can cause issues to your esc or battery. However, if you can find a way to turn your cranking into a charging system, where you hook the cranking with a system that generates energy as a charger to recharge the battery instead of regenerating into the pack again, it should be possible. But I have never seen this happen… at all.
There’s a way to do it though, but I’ll see if I can find more info. You can set one esc to regen current 0 and the other to a certain amp to regen. But you might run into an issue where your crank has to be wired to make it feel as it you’re stopping your bike by pedaling. It could work if you figure this out.
Edit: something like this:
You might not be able to read this… I was able to bypass it.
But they’re using the braking system we use in esk8. You want your cranking to be the regen instead. I enjoyed learning about this.
@JgoFast , I’m thinking the same thing, but I’m hoping someone in this forum with electrical know-how and vesc experience can give me a thumbs up.
According to this video, you can see VESC creator Bejamin Vedder setting up a separate ADC throttle for braking/regen only, which means the vesc has the capability for variable braking/regen. If you don’t recommend cranking because of a certain resistance, shouldn’t I be able to vary the resistance on a separate throttle?
Basically I’m more concerned if the vescs can handle this without blowing up or making magic smoke. Batteries are very simple and should work along a range of charging-to-drawing depending on the present demands. I’m also looking to build a batt with a high recharge rate so I’m not worried there, but I’m unsure if 1 vesc drawing power while another vesc puts power back into the system will cause detriment towards eachother. Normally a vesc switches (or multiples over CANBUS) between driving and regen; it does/they do one or the other but never both. In this case I’m making 2 different vescs share the same battery while they do their own thing.
I have a lot of vesc experience and I get my EE degree this may. I’m confident in my logic, that’s why I was telling you to read up on series hybrid so you can see they have been doing this kind of thing for years. Yes Vesc’s can do regen without blowing up, how else would any of these longboard have brakes? Energy is energy and one is putting it into the system and one is taking from. And your battery acts as a capacitor to smooth any ripple